1. Field of the Invention
The present invention relates to a wind deflector in the field of motor vehicles.
2. Related Technology
Although useable in any desired regions of a motor vehicle, the present invention and the problem on which it is based are explained in more detail with regard to a sliding roof of a motor vehicle. The present inventive concept can also be used, for example, on windows, sun roofs or panorama roofs of a vehicle.
A generally known problem with a motor vehicle sliding roof is that, when the cover is open, periodic fluctuations in pressure may occur in the interior of the vehicle when the vehicle is moving at low to medium speeds. Said periodic fluctuations in pressure are undesirably perceptible, mainly acoustically, in the form of “rumbling”. Wind deflectors are generally used so as to avoid said fluctuations in pressure.
A wind deflector generally has the function of improving the flow conditions of the motor vehicle when, for example, the cover of a sliding roof is an open position. The wind deflector is usually arranged at the front end, as seen in the direction of travel, of the roof opening opened up by the sliding cover, and is transferred from a retracted position, in which is located below the outer surface of the vehicle roof, into a deployed position when the sliding cover is opened.
Conventional wind deflectors have a connecting element which is arranged in a curvature of a sheet-metal frame, which is assigned to the wind deflector, in the roof of the vehicle. The curvature is formed downward in the direction of the vehicle interior in the sheet-metal frame and, in addition to the connecting element, accommodates a wind deflector net when the sliding cover is closed.
In the embodiment described above, a first problem arises from the fact that the curvature in the roof frame reduces the vehicle interior in the region of the roof lining and therefore has an adverse effect on the comfort of the vehicle.
Furthermore, wind deflectors of this type have a deployment element arranged over the connecting element, with the wind deflector net being fastened in a manner such that it can be stretched out between the deployment element and the connecting element. In the deployed position of the deployment element, one section of the wind deflector net bears taughtly against a front roof edge of the roof opening. This has the purpose of preventing relative wind from flowing into the sheet-metal frame below the roof, and of therefore being able to reduce relative wind noises.
Furthermore, in the deployed position, the wind deflector has a deployment height which specifies the distance between an upper side of the roof and an upper edge of the deployment element. If said deployment height deviates by only a few tenths of a millimeter from a desired deployment height, the noise-reducing effect of the wind deflector deteriorates.
Added to this is the fact that vehicle roofs increasingly have glass elements or fixed glass elements which are arranged in front of and behind the sliding cover of the sliding roof. Said elements have the purpose of improving the feeling of space for vehicle occupants. Such glass elements are typically adhesively bonded in in the vehicle roof. When the glass elements are adhesively bonded in, deviations with regard to the precise position of the glass elements may occur, for example due to an uneven application of the adhesive (adhesive bonding tolerance).
Furthermore, such glass elements are slightly differently curved (glass curvature tolerance), this arising from the production process. If such glass elements form the front roof opening edge, then the latter is subject both to the glass curvature tolerance and the adhesive bonding tolerance of the glass element. In total, said tolerances may be in the region of several millimeters.
This gives rise to a second problem which consists in that the deployment height of the deployment element and therefore the reduction in noise is affected by the position of the roof edge. Furthermore, creases may form in the deflector net and therefore a disadvantageous production of noise may occur if the roof edge, in the region in which it bears against a deflector net, is arranged obliquely with respect to the deflector net. Consequently, the adhesive bonding tolerance and the glass curvature tolerance have a direct effect on the function of the wind deflector.